Show nation culture (2.6) and gain per turn in client
In the augmented2 modpack, city and nation culture really matters. With the 2.6 client, I found myself repeatedly opening the Demographics report to find out my nation's current culture.
Nation culture was added to the info popup in feature #821946, but only from 3.0+ because "client in S2_6 does not know the total amount of player culture".
I think that the evaluation in
player_culture(), that uses history from server and evaluates performance effects on the client, would give a good enough result for most sensible rulesets? If not, I think it would be worth adding an optional capability to let new 2.6 servers send the real value to the client (like feature #820730 but without the embassies part), and show that in the client if available.
Also, on all branches, it would be useful to see the expected gain per turn (from history). Currently that has to be evaluated on the client in all branches, and I think these kind of forecasts are probably mostly fine like that, although it's possible to construct a ruleset where the forecasts are misleading due to incomplete client knowledge.
Attached patch uses client-side knowledge (for both on 2.6).
This patch only helps those clients that use
get_info_label_text_popup() somewhere (i.e., not the SDL clients). (In the Gtk clients it's available by left-click on the left civilization info pane; in the Qt client it's a tooltip on the left sidebar gov/warming/etc icons.)
(Putting this in the tooltip is a compromise between making it available at all, and taking up valuable screen real estate in rulesets where culture isn't a thing. In future, I wonder if it is worth adding some booleans to the ruleset format, so that rulesets can indicate "culture is important", "plague is important" etc and the client can adapt its display accordingly. Or, probably, semantics of "suppress plague display".)